Dissociation of hydrogen molecules in collisions with light alkali ions. II. Li +-H 2

Abstract

The dissociation of a ground state H 2 molecule in single collisions with a Li + ion has been studied using a time of flight technique over a large range of center of mass scattering angles (30° ⩽ υ ⩽ 180°) and collision energies (16 eV < E cm < 55.5 ev). The results have been transformed into the center of mass system to obtain inelastic differential cross sections (contour maps). In contrast to most other scattering experiments on collision induced dissociation, the results at high energies ( E cm > 40 eV) cannot be explained by a two-step mechanism. Instead dissociation appears to occur in a time comparable to the collision time. The results are consistent with several collision models. Of these the spectator model in which only one of the atoms of the molecule is struck by the incident ion is favored since it is in good agreement with the differential cross sections for backward scattering.